Abstract: The invention relates to a method for the overload protection of a mobile crane, in particular of a crawler-mounted crane, in which component-related geometrical data are stored in a memory. In accordance with a selected set-up, the geometrical data are put together to form a physical simulation model on a simulation computer. Taking into account real measurement data, the required geometrical data, centre of gravity data and forces are calculated, and from these the cut-off values. The crane is switched off when these cut-off values are reached.

Abstract: An apparatus, program product, and method for estimating the stress intensity factor ratio (SIFR) of a material. The material is supported on a support and a load is applied to the material using a load member. A pair of strain components are measured using a strain gage attached to the material, and are stored in memory. The strain gage may be a rosette strain gage, for example. A processor calculates a ratio of the stored pair of strain components to thereby provide an estimate of the SIFR of the material. Advantageously, this estimate of the SIFR of the material is readily provided. Also advantageously, the estimate may be provided in a manner that is non-destructive to the material. The processor may additionally calculate the stress level of the material based on the estimated SIFR.

Abstract: An apparatus and method for detecting twist in an articles such as pieces of lumber being carried on a high-speed longitudinally moving conveyer use a non-contact scanning technique according to which a pair of transverse scan line beams is directed onto a surface of the article in spaced relationship in the conveying direction, and successive scans of corresponding simultaneously scanned pairs of spaced transverse areas on the article are repeatedly performed while the article is conveyed, to generate profile data characterizing position of each transverse area in a reference system. The profile data characterizing the respective position of both transverse areas is compared with one another to generate partial twist indicative data associated with each scan, followed by a summation of the partial twist indicative data associated with all scans to obtain an indication of the twist in the considered portion of the article.

Abstract: A method, system and computer program product are provided for automated fatigue and structural analysis of a structural element. The method, system and computer program product consolidate and manage the fatigue and structural analysis tools and are responsive to user requests for fatigue and structural analysis of elements based upon user-provided information regarding the element. As such, the appropriate fatigue and structural analysis tools are automatically selected and run, and the output of the tools is automatically evaluated to provide immediately useful fatigue and structural analysis results to the user without requiring further manual input. Thus, people without specialized training can quickly obtain fatigue and structural analysis results for an element. In addition, because the fatigue and structural analysis tools are integrated, the tools may be accessed from remote locations via a computer network.

Abstract: This invention includes the generation of forming information and its manipulation scheme as a method to form curved plates in ship hull-pieces. This invention consists of three components as follows: one is to construct and utilize a database which includes data about flat plates, objective curved plates, plates which are being formed, and their forming information, another is to infer new forming information with an artificial neural network system, and the third is to obtain forming information through calculating in-plane and bending strains. In the third, initial forming information is obtained by calculating strains from relationship between flat plates and objective curved plates. And new forming information is yielded through calculating the strains from relationship between partially formed curved plates and objective curved plates.

Abstract: The present invention relates to a device and method for measurement of tensile strength of materials, especially for indirectly measuring the tensile strength of weak rock and hard soil. The probe of the measuring device comprises a cylindrical body with an expandable flexible membrane designed to apply a uniform pressure to the walls of a cavity, such as a bore hole. There is no need to cut a core specimen to a particular shape for measurement, thus making it an attractive option for measurement of weakly bonded rock and hard soil.

Abstract: Systems and methods are disclosed that can provide estimates of elasto-plastic properties of material samples using data from instrumented indentation tests. Alternatively, or in addition, estimated load-depth curves can be constructed by certain methods and systems provided based on known mechanical properties. Some disclosed systems and methods use large deformation theory for at least part of the analysis and/or determinations and/or may account for strains of at least 5% in the area of contact between the indenter and the material sample, which can result in more accurate estimates of mechanical properties and/or deformation behavior.

Abstract: An apparatus for measuring three-dimension information of an object has an image reader, a corresponding point detector and a three-dimension information calculator. The image reader reads a pair of images recorded in a recording medium in the apparatus. Note that, the object is cylindrical and a pair of occluding contours is reflected in each of the pair of images. The corresponding point detector detects at least one pair of corresponding points, which is an imaginary pair of images of at least one measuring point positioned on a central axis, on a pair of bisecting lines. The three-dimension information calculator calculates the three-dimension position of the at least one measuring point on the basis of the at least one pair of corresponding points by applying a triangulation method.

Abstract: A method for selecting a suitable workpiece having a material composition and a thickness for forming an article. The method calculates expected strain resulting from straight bends, stretch flanges, and shrink flanges utilizing customized strain correlations developed from strain test data of work piece samples. The calculated straight bend strain and stretch flange strain from multiple bends are then compared with the material yield strain to determine workpiece suitability. The shrink flange strain is compared with the material buckle stain to determine workpiece suitability. The method also calculates a spring back deformation for determining suitability of the workpiece and the press forming procedures.

Abstract: A signal processing technique which correlates eddy current inspection data from a tube having a critical tubing defect with a range of predicted burst pressures for the tube is provided. The method can directly correlate the raw eddy current inspection data representing the critical tubing defect with the range of burst pressures using a regression technique, preferably an artificial neural network. Alternatively, the technique deconvolves the raw eddy current inspection data into a set of undistorted signals, each of which represents a separate defect of the tube. The undistorted defect signal which represents the critical tubing defect is related to a range of burst pressures utilizing a regression technique.

Abstract: Techniques for evaluating curvatures in line features embedded in a different material layer formed on a substrate. A model based a uniform layer formed over a substrate may be used to represent a structure with parallel line features embedded in a layer formed over the substrate. The curvatures of the uniform layer due to an elastic distortion along a first direction substantially parallel to the line features and along a second direction orthogonal to the first direction are determined. Next, the curvatures of the uniform layer may be used as respective curvatures of each of the line features.

Abstract: An electronic monitor is disclosed which continuously monitors the sound emanating from rotating machinery, non-rotating equipment, or any other sound-producing process or environment, as a means of detecting abnormalities and thus determining the operating condition thereof. The monitor continuously computes the power spectrum of the monitored sound and has two modes of operation: learn and operate. The monitor is placed in the learn mode during a time when the machine or process to be monitored is known to be operating normally. During the learn mode, the maximum and minimum acoustic power output from each of a plurality of digital bandpass filters is continuously maintained and updated in data memory as the acoustic signature of the machine or process being monitored.

Abstract: A fatigue monitoring system and method is disclosed in which a stream of data relating to the stresses experienced at a plurality of locations over the structure during operation is applied to a neural network trained to remove data stream values deemed to be in error. The data from the neural network is then processed to determine the fatigue life.

Abstract: The latent stress in a material can be measured using critically refracted longitudinal ultrasonic technique. The system uses a frame to hold a hydraulic piston. The piston is used to apply an adjustable force against the probes. A signal is initiated by a first transducer. The signal is angled against the piece under test so as to create a critically refracted wave along the piece. The delay time to receive the wave at a first and second probe is measured. The delay time correlates to a stress in the piece.

Abstract: Diameters and the number of respective wires are inputted, and a diameter of a virtual wire formed by converting a wire bundle to a model through a predetermined arithmetic expression derived from rule of thumb, and based upon this, a flexure life estimating process of the virtual wire is carried out. It is possible to easily estimate the flexure life and also to estimate the flexure life and obtain the results immediately after an application subject and a wire harness to be placed have been designed; thus, it becomes possible to shorten the developing period.

Abstract: A method and apparatus are provided for the detection, through nonlinear manipulation of data, of an indicator of imminent failure due to crack growth in structural elements. The method is a process of determining energy consumption due to crack growth and correlating the energy consumption with physical phenomena indicative of a failure event. The apparatus includes sensors for sensing physical data factors, processors or the like for computing a relationship between the physical data factors and phenomena indicative of the failure event, and apparatus for providing notification of the characteristics and extent of such phenomena.

Abstract: The invention provides a method for operating a controlled stress rheometer in a controlled strain mode to follow a demand strain Xd in a sample having applied thereto a variable demand force Td,, inducing an actual strain X including the steps of:

Abstract: A method and apparatus for determining the fatigue life of a structure calculate, in real time, the values for the magnitudes of the stress forces imposed at a particular location on the structure, from one or more sensed structural parameters. Also, the associated temperature values of the structure may be calculated or measured. The calculated stress data are continuously examined, in real time, to determine if the direction of their magnitude is increasing or decreasing. If a change in direction is indicated, the previously stored peak data point in the increasing direction is paired with the previously determined peak data point in the decreasing direction to form a cycle pair. The structural fatigue life is then determined, in real time, from this cycle pair.

Abstract: An apparatus and method that determines a maximum road friction coefficient for each wheel regardless of whether the tire is in a predetermined drive slip state, and whether the wheel is a driving wheel. The braking force of each wheel is calculated, and the longitudinal force of the tire of each wheel is calculated. Then, the driving force of the vehicle is calculated, and the lateral force of the tire of each wheel is calculated. Next, the reaction force of the road to each wheel is calculated, and the vertical load of each wheel is calculated. Finally, the ratio of variation in reaction force of the road to variation in composite slip ratio is calculated for each wheel. The sum of the ratio of the reaction force of the road to the vertical load, and the product of a predetermined coefficient and the ratio of variation in reaction force of the road to variation in composite slip ratios is calculated for each wheel as the maximum road friction coefficient.

Abstract: The latent stress in a material can be measured using critically refracted longitudinal ultrasonic technique. The system uses a frame to hold a hydraulic piston. The piston is used to apply an adjustable force against the probes. A signal is initiated by a first transducer. The signal is angled against the piece under test so as to create a critically refracted wave along the piece. The delay time to receive the wave at a first and second probe is measured. The delay time correlates to a stress in the piece.

Abstract: A method for predicting impact performance of an article constructed of a material includes: applying physical properties of the material to a constitutive model; performing biaxial property tests on painted samples of the material shaped according to test geometries; performing finite element simulation analysis on the test geometries using the constitutive model; determining maximum principle stress levels from the finite element simulation analysis corresponding to experimental failure displacements obtained from the biaxial property tests; and applying the maximum principle stress levels and the constitutive model to finite element simulation analysis of the article.

Abstract: The present invention discloses a testing system and a testing method for a structure which tests a structure made of a test piece structure and a numerical model virtually connected to the structure. A simulated structure including a frame, an actuator and a reaction force measuring device is mounted on a foundation on which a shaking table is also mounted. Only the test piece structure is mounted on the shaking table. The motion of the shaking table 5 which is generated at the time of shaking the test piece structure using the shaking table and the actuator is measured by a shaking table motion measuring device, while the reaction force generated by the test piece structure is measured by a reaction force measuring device. Using these measured values and the numerical model stored in a digital computer, the motion of the test piece structure after a predetermined period for the motion of the simulated structure is calculated.

Abstract: A travelling track on which a plurality of movers travel is divided into sections of various lengths. A position/velocity calculator obtains the position and velocity of the movers in the sections, using the position and velocity of each mover having passed the boundary of the section in which the mover travels. A collision-chance determiner determines whether there is a great chance that each pair of neighboring movers will collide with each other, using the position and velocity obtained by the position/velocity calculator. An emergency stopper stops a pair of neighboring movers that the collision-chance determiner determined that they would collide with each other, in an emergency.

Abstract: The invention concerns an automatic and continuous measurement and control method of the tension and/or running of the yarns fed into knitting machines. It consists of permanently placing, along the route of each yarn towards the machine a device 15 for measuring the tension and/or running of the yarn, of connecting the devices to a management computer 16, programmed to recognise, display and process the reading data coming from each device and of the issuing by the computer of correction signals for the tension and/or running values of every yarn at every machine supply station and/or of the knitting in progress, when these values go beyond the prefixed limits.

Abstract: A distributed stress wave analysis system is disclosed for detecting structure borne sounds cause by friction. The detected information is processed using feature extraction and neural network artificial intelligence software. The system consists of stress wave sensors, interconnect cables, and preferably three modules: (1) distributed processing units, (2) maintenance advisory panel, and (3) laptop computer. A derived stress wave pulse train which is independent of background levels of vibration and audible noise is used to extract signature features, which when processed by neural networks of polynomial equations, characterize the mechanical health of the monitored components. The system includes an adjustable data fusion architecture to optimize indication thresholds, maximize fault detection probability, and minimize false alarms.

Abstract: A composite material having a microstructure model is provided with a continuous matrix of microstructure entities such as particles and grains that rotate under both remotely applied stresses and induced concentrated stresses from nearby cracks, pores and smaller particles, all networked within the matrix. The rotation microstructure entities are smooth closed contours that are elliptically-shaped. A net moment results on the boundaries of the microstructure entities effecting fracture toughening of the material. Small particles and other microstructural entities may reduce the attenuation of, transmit, and counteract the stresses induced by the rotating microstructure entities. The induced stresses counteract those stresses and strain energy densities that promote crack propagation. The result is a microstructure free of laminates, coatings, fibers and fiber architectures that effect toughening of the material against fracture.

Abstract: The invention relates to a method for the overload protection of a mobile crane, in particular of a crawler-mounted crane, in which component-related geometrical data are stored in a memory. In accordance with a selected set-up,. the geometrical data are put together to form a physical simulation model on a simulation computer. Taking into account real measurement data, the required geometrical data, centre of gravity data and forces are calculated, and from these the cut-off values. The crane is switched off when these cut-off values are reached.

Abstract: A method is provided for determining the rotational stiffness of a drill string for drilling of a borehole in an earth formation, the drill string having a bottom hole assembly (BHA) and an upper end driven by a rotational drive system. The method comprises the steps of determining the time derivative of the drill string torque during drilling of the borehole at a selected time when stick-slip of the BHA occurs, determining the nominal rotational speed of the drill string at an upper part thereof and at said selected time, and determining the rotational stiffness of the drill string from a selected relationship between said time derivative of the drill string torque and said nominal rotational speed at the upper part of the drill string.

Abstract: Provided are methods and apparatus for determining from indentation testing the preexisting stress and/or effective strain in a section of a material. The invention also provides methods and apparatus for determining the variation of the stress with depth in the material (e.g. the gradient). According to the invention, first data are provided from an indentation test of the stressed (or strained) section. The stress (or effective strain) can then be determined from the first data and from second data characteristic of the material, such as a stress-strain curve. Second data can also be obtained from an additional indentation test of a section having a known stress. The methods provided herein are suitable for programming on a general purpose computer or calculator.

Abstract: A method for estimating the life of an apparatus under a random stress amplitude variation, involving determining a probability density function of a cumulated damage quantity and estimating the life of the apparatus on the basis of the probability density function, characterized by: approximating a damage coefficient indicative of a damage quantity per unit by a linear expression when the random stress amplitude variation is in a narrow band; and representing the random stress amplitude variation &sgr;(t)(instantaneous) in terms of the sum of a time averaged value &sgr;(t)(mean) and a stochastic variation &sgr;′.

Abstract: The present invention relates to a device and method for measurement of tensile strength of materials, especially for indirectly measuring the tensile strength of weak rock and hard soil. The probe of the measuring device comprises a cylindrical body with an expandable flexible membrane designed to apply a uniform pressure to the walls of a cavity, such as a bore hole. There is no need to cut a core specimen to a particular shape for measurement, thus making it an attractive option for measurement of weakly bonded rock and hard soil.

Abstract: In a signal measuring method and apparatus, a digital signal processor (5) including a digital signal generator (5A) generates a digital signal, which is converted by a digital-to-analog converter (2) into a sinusoidal analog signal that is applied as a supply voltage to the transducers, such as load cell strain gages arranged in a bridge circuit (1). The analog supply voltage signal is modulated by the measurement voltage in the bridge circuit (1). The resulting modulated signal is amplified if necessary in an amplifier (3), and is then digitalized in an analog-to-digital converter (4) operating with a sampling frequency at least twice the carrier frequency and preferably corresponding to a whole number multiple thereof. The digital signal processor (5) carries out a Fourier transform of the digitalized signal to calculate the magnitude and phase of the measurement voltage, which may then be used for the complex calculation of zero point compensations and adjustment calibrations.

Abstract: A method (100) for predicting distortion of a sheet metal during a sheet forming process to form the sheet metal into a part. The method (100) of the present invention is for use with a computer including memory and sheet forming tools. The method (100) comprises applying (104-116) the radial return method to compute the total stress for the anisotropic hardening rule of Mroz. The method (100) of the present invention does not divide a given strain increment into hundreds of subintervals as long as the movement of the center of the active yield surface is along a fixed path. If a break occurs, the given strain increment is divided into a few segments (110).

Abstract: A variable rate test joint comprises a housing and a shaft mounted within the housing. A hexagonal head is provided for coupling a tool to be tested to the shaft. In use a frictional braking torque is applied to the shaft. A computer controls the magnitude of the braking torque applied to the shaft as a function of time.

Abstract: A method of and apparatus for checking a wrapping state of a wrapped roll having end face covers by detecting the force required to press-fit a bushing into a cylindrical core tube and comparing the detected force with a threshold value which is based on the correlation between the force required to press-fit the bushing into the cylindrical core tube and the state of tucking of the end face covers.

Abstract: The characteristics of the wire are calculated, the wire having a cross-sectional shape which is substantially uniform along its length and having a length long enough in comparison with a diameter being deformed. The wire is divided into a plurality of elements with predetermined spacing along the length. When the wire is deformed, the shape of the wire after the deformation is determined. In the determined shape, a tangential stiffness equation using the element as a basis is calculated, and the calculated tangential stiffness equation is translated into a tangential stiffness equation using the whole of the wire as a basis. A global stiffness equation representing the whole wire is calculated from the tangential stiffness equation obtained by the translation. A load or a displacement produced in each portion of the wire is calculated from the global stiffness equation and the determined shape of the wire.

Abstract: The present invention is embodied in an apparatus and method for generating fatigue spectra on a chosen aircraft for which a Finite element model is available and for which a library of external load summations at key interfaces and key fundamental parameters are available from an aeroelastic analysis. The fatigue spectra generation system of the present invention represents a profile of stresses endured by the aircraft due to numerous events, such as ground and maneuver events, occurring during the life of the aircraft. The system calculates a total stress based on load and unit conditions associated with outside events by factoring up the unit conditions to derive individual stresses for each event and by summing all unit conditions.

Abstract: Stress, strain and displacement in two-dimensional regions can be calculated by computerized techniques. In the x-y plane, a region is discretized into four-node finite elements such as quadrilaterals and triangles with side nodes. Each such element has eight distinct deformation modes. These correspond to three rigid-body displacements, three uniform strain profiles for compressible materials or two deviatoric strain fields accompanied by an isotropic pressure for incompressible materials, and two flexures. Pointwise equilibrium requires the bending shapes to be functions of Poisson's ratio. Nodal equilibrium and compatibility are satisfied for prescribed loads implementing exact differentiation and integration.

Abstract: A method for analyzing the strength of a structure and an apparatus using the same which are capable of more simply and accurately computing the stress of each element of the structure by selectively grouping the elements of the structure, which receive a lot stress, and analyzing the stresses of the grouped elements with respect to the entire structures. The method includes the steps of a first step for grouping a concerned element of an object structure and computing a strength of the concerned element, a second step for setting a unit load value and computing a stress of the concerned element, a third step for changing a stress value corresponding to the unit load value into a related function with respect to the entire elements, a fourth step for computing a stress based on an actual load value based on the related function and actual load value, and a fifth step for analyzing a strength of a corresponding structure based on the stress based on the actual load value.

Abstract: A method is disclosed for developing a sheet metal forming process prediction method which is based on the application of an anisotropic hardening rule of plasticity in the mathematic theory.

Abstract: During dozing operation, the amount of earth (i.e., load factor) accumulated on the front face of a blade is automatically detected independently of the operator's perception and, based on the detection, the dozing operation is automatically shifted from digging to carrying. The load factor is calculated by obtaining a horizontal reaction force and a vertical reaction force exerted on the blade during digging and by calculating the ratio of the vertical reaction force to the horizontal reaction force. When the load factor reaches a specified value, the blade is automatically controlled to incline backward to hold the earth.

Abstract: The tension in an optical fiber being drawn from a preform is monitored by sensing its motion transverse to the drawing direction and analysing the sensed motion using an autoregressive time-series model to provide a power spectrum. One of the peaks of the spectrum is identified as associated with the fundamental natural frequency of the drawn fiber and the frequency of that peak is used in a calculation of the tension of the fiber.

Abstract: The present invention provides a method of monitoring a cyclic system comprising a plurality of cyclic means, comprising measuring a single parameter for the complete cyclic system, and, during a learning mode, cycling the cyclic system a plural number of times, and from the measured value of the parameter, providing a range of acceptable values, and during a subsequent monitoring mode comparing the measured value of said parameter with said range of values, and providing an output signal if the measured value of the parameter is outside said range of values.

Abstract: The present invention provides a system and method for measuring weight and speed of a moving railcar through dynamic processing of a voltage signal from at least one strain gauge embedded into a rail on the railroad track. The system comprises at least one strain gauge, an amplifier circuit, a converter circuit, and a first processing means. The method performed by the first processing means is a state machine expert system algorithm which dynamically determines the baseline non-stressed voltage level and the peak voltage level upon the strain gauge being stressed by a moving railcar passing over the strain gauge. The method further provides for eliminating the effects of debounce on the weight calculations by continuously monitoring the voltage signal from the strain gauge for a predetermined period of time after an initial peak is detected and updating that value if a greater peak is detected within the predetermined period of time.

Abstract: A NASTRAN-programmed computer calculates force and moment data for a structure including joints of interest. The NASTRAN data is read by a computer programmed with the invented program. For each joint, the user selects the members which contribute forces to the joint, and also selects the nearest grid point. A computer programmed with the invented program calculates the resultant force and moment at the proximate grid point. The force and moment are originally defined in a global coordinate system, subsequently transformed into a local coordinate system, and then translated to the centroid of the joint's fastener pattern. Axial and shear forces for each fastener are calculated for the nominal case wherein all of the fasteners are operative. Furthermore, each fastener, in turn, is assumed not to transmit axial force and the resulting fail-safe axial forces respectively acting on the remaining operative fasteners are calculated.

Abstract: Residential wood home structures are evaluated and classified according to a defined risk level relative to damage likely to be caused by earthquake shaking or wind forces. Susceptibility to damage is evaluated and predicted by a probabilistic software engine based on existing databases of geologic and/or wind data coupled with specific structural characteristics information obtained by an onsite inspection of the structure. The software engine combines these data sets, and produces a report with a reliable, quantified risk rating that can be used by insurance companies to make decisions regarding offering of insurance and rates of insurance. The report is also used by homeowners as an evaluation factor in deciding to strengthen the structure against earthquake and/or wind storm damage.

Abstract: A percussion system including at least one force transducer developing a variable resistance output based upon a force exerted upon its surface, an interface providing an interface output based upon the analog output of the force transducer, and a digital processing system coupled to the interface. The analog input is preferably a variable resistance, and the interface output is preferably a pulse having a width related to the variable resistance. The interface preferably includes a capacitive member to form an RC circuit with the force transducer, and circuitry responsive to the RC circuit to produce a digital output. The digital processing system stores the digital output of the interface in memory and processes the digital output with other digital outputs of the interface to perform a computer implemented process such as producing a synthesized drum sound.